Abstract: [Objective] To compare the clinical consequence of partial transplantation of the fifth carpometacarpal joint versus arthroplasty in the treatment of metacarpophalangeal defects. [Methods] A retrospective study was conducted on 32 patients who underwent surgical treatment for metacarpophalangeal defect due to trauma in our hospital from March 2016 to December 2022. According to preoperative surgeon-patients discussion, 16 patients were treated with partial transplantation of the fifth carpometacarpal joint, while other 16 patients were with then conventional arthroplasty. The documents regarding perioperative period, followup and imaging were compared between the two groups. [Results] All patients in both groups had corresponding surgical procedures performed successfully without serious complications such as neurovascular injuries. The transplantation group consumed significantly longer operative time [(137.0±16.4) min vs (102.5± 12.5) min, P＜0.005] and more intraoperative fluoroscopy times [(28.1±1.4) vs (23.1±0.8), P=0.006] than the arthroplasty group. However, there were no significant differences in intraoperative blood loss, total incision length, hospital stay, hospitalization cost and postoperative plaster fixation time between the two groups (P＞0.05). With time elapsed during the followup period lasted for (17.7±4.0) months in a mean, the VAS and DASH scores in both groups were significantly decreased (P＜0.05), while grip strength, metacarpophalangeal ROM and Carroll hand function test scores were significantly increased (P＜0.05). The transplantation group proved significantly superior to the arthroplasty group in terms DASH score [(83.2±3.9) vs (89.9±5.4), P=0.003; (55.3±6.2) vs (61.4±6.9), P=0.022] 1 and 3 months postoperatively, metacarpophalangeal ROM [(62.5±5.4)° vs (56.6±7.3)°, P=0.033; (82.2±4.3)° vs (76.9±5.2)°, P=0.004] and Carroll score [(77.8±4.0) vs (74.9±3.2), P=0.022; (92.6±3.6) vs (88.5±3.2), P=0.004] 3 months after operation and at the latest follow-up, as well as grip strength [(26.8±3.7) kg vs (22.9±3.5) kg, P=0.009; (48.9±5.8) kg vs (44.1±5.0) kg, P=0.009] 1 month after surgery and at the last follow-up. As for postoperative imaging, there was no significant difference in fracture healing time between the two groups (P＞0.05), whereas the transplantation group had significantly greater relative joint space than the arthroplasty group at the last follow-up [(1.03±0.68)% vs (0.86±0.11)%, P= 0.002]. [Conclusion] Partial transplantation of the fifth carpometacarpal joint for metacarpophalangeal partial defect, especially with tendon and ligament insertion defect, does better rebuild the integrity and stability of the joint, and is more conducive to the functional recovery of the metacarpophalangeal joint.